Brazilian Jiu-Jitsu (BJJ) is based upon grappling and ground fighting with the aim of gaining a dominant position and using joint-locks
and chokeholds to force submission. It has the principle that a smaller, weaker person using leverage and proper technique
can successfully grapple against a bigger and stronger assailant.

The
advantage of a larger, stronger opponent comes from superior reach and more powerful strikes, both of which are negated if
on the ground. BJJ includes many techniques to throw or drag opponents to the ground using the hips and shoulders. Once the
opponent is on the ground, a number of skills manipulate the opponent into suitable position for the application of a submission
hold. Achieving a dominant position on the ground is one of the hallmarks of the BJJ style, and includes effective use of
the guard position to defend oneself from bottom, and passing the guard to dominate from top position with side control, mount,
and back mount positions

The majority of submission
holds can be grouped into two broad categories: joint locks and chokes. Joint locks typically involve isolating an opponent's
limb to force the joint to move beyond its normal range of motion and signals defeat by submitting.

Alternatively,
one could apply a choke hold, disrupting the blood supply to the brain, causing unconsciousness if the opponent refuses to
tap out. A third, and less common type of submission hold is a compression lock, where the muscle of an opponent is compressed
against a hard, large bone (commonly the shin or wrist), causing significant pain to the opponent.

However, most joint
locks involving the wrist, elbow, shoulder or ankle are permitted. This includes driving knuckles into pressure points, holding
their opponent's head in order to tire out the neck (called the "can opener") and putting body weight on top of the sternum,
floating ribs.

Most BJJ "Strangles"
involve constriction of the carotid artery and “Chokes” involving constriction of the windpipe. Blood chokes (strangulations)
directly cut the flow of blood off to the opponent's brain causing a rapid loss of consciousness without damaging the internal
structure like Air Chokes which damage Trachea.

Being
"choked-out" in this way is actually relatively safe as long as the choke is released soon after unconsciousness.

Sport Brazilian Jiu-Jitsu's
focus on submissions without strikes.

Training
methods include technique drills in which techniques are practiced against a non-resisting partner.